Press for cutting cardboard



H. BOBST March 28, 1939.

PRESS FORJGUTTING CARDBOARD Filed Nov. 9, 1957 2 Sheets-Sheet 1INVENTORI 76 5 75 HENRI BOBST 3%m%9 ATTORN EMS H BOBST March 28, 1939;

CARDBOARD PRESS FOR CUTTING 2 Sheets-Sheet 2 Filed Nov. 9, 1937INVENTOR- HENRI! 505st. J

' Z ATTORNEYS lit Patented Mar. 28, 1939 UNl'lD STATES- ATENT OFFICEApplication November 9, 1937, Serial No. 173,548 In Switzerland November18, 1936 .4 Claims.

This invention relates to a press, serving especially for the cutting ofcardboard worked in a continuous Web.

The press according to the invention is characterized by a fly wheelwhich maintains a speed of rotation which is substantially constant andby a device which makes it possible to give the press two differentworking speeds constituting a fast and a slow rate of working.

The press will, in preference, be provided with means to prevent thepress from stopping in the neighbourhood of its dead centre, where itfurnishes its productive effort, said means remaining inactive when thepress is working idle.

The accompanying drawings show two embodiments of the press according tothe invention and given by way'of example.

Fig. l is a side view of the first embodiment, which is drivenelectro-mechanically and which comprises means to prevent the press fromstopping, when it is furnishing its productive eifort.

Fig. 2 is a corresponding plan view.

Fig. 3 shows the diagram of the connections of this first embodiment.

In the embodiment shown in Figs. 1 to 3, a motor l drives the press ofwhich the head 2 guided by a frame 3 effects an alternative verticalmovement, and cuts by means of a steel punch a web of cardboard 4, whichadvances intermittently from a reserve, which it is assumed is situatedon the left hand of the drawing, then said web after it has been punchedis cut by cutters 5 and eventually passed to a printing group whichwould be'situated on the right hand, but is not shown on the drawings.

The head 2 of the press is actuated by means of belts 6, of a two speedclutch, which will be described more in detail hereinunder, of a shaft7, of a pinion 8, of a toothed wheel 9, of a shaft l0 carrying theeccentrics II and the connecting rods l2. Whenever the eccentrics IIpass their lower dead centre, i. e. the inverse position to that shown,the head 2 is lowered and cuts off that part of the web of cardboard 4under same.

It is however possible to prevent the punching operation from takingplace by acting on the lever l3, which is connected to an eccentric l4controlling a connecting rod l5 which is itself connected to a lever l6,and this makes it possible to modify the position of an eccentric llturning in the head of the connecting rod 12 which same connects to thehead 2; a similar eccentric is situated on the other side of the pressand is made integral with the first eccentric 56 by means of the shaftHi. In fact, by bringing the lever 13 into the position l3 shown in dotand dash line, the connecting rod I5 is caused to rise and the lever I6is caused to rotate counter-clockwise in respect'to the drawings, andthe corresponding rotation of the shaft l8 and of its eccentrics causethe head 2 to rise slightly in relation to the connecting rod I2, whichcan'no longer apply the steel punch against the corresponding platen ofthe press, upon which the web of cardboard lies.

As for the two speed clutch, it is constructed as follows:

A fly Wheel l9 which is driven directly by the motor rotates freelyround a sleeve 20, which is connected to the shaft 1 by means of the key2!.

The fly wheel as it rotates drives the planet wheels 22, 23 which areformed like toothed pinions and which are integral with eachother, theplanet wheels 22 being however smaller in diameter than the planetwheels 23. The planet wheels 22 catch in a corresponding gear of thesleeve 20, whereas'the planet wheels 23 catch in another gear of a drum24 of a cheek brake, the cheeks of which are designated by the referencenumeral 25. Frictional members 26 are mounted in slots of drum 24 beingfree to slide radially in these slots and capable of connecting the drumwith the fly wheel by their application against an inside surface 21 ofthe latter, a cone 28controlled by a fork 29 being provided for thispurpose.

It can easily be seen that in the position shown of the differentmembers, that is to say when the brake 24 is not braked and when thecone 28 is taken out of said drum, the press cannot be driven. In 'fact,in this case, the rotation of the flywheel causes the rolling of theplanet wheels 22 overthe gear, of thesleeve 2U,'Whl0h as it is connectedto the press, offers a resistance which forces the planet wheels 22 torotate. As the planet wheels then rotate at the same speed but act onthe gear of the drum 24 which is of smaller diameter than the sleeve 20,the result is a relatively slow movement of the drum and in a directionwhich is contrary tothat of the rotation of the wheel.

If now by acting on the cheeks 25, the drum is immobilized, the slowmovement given previously to the latter will have to be transmitted tothe sleeve 20 and in a contrary direction, that is to say in the samedirection as the rotation of the fly wheel. In fact, at this moment, itis the planet wheels 23 that are obliged to roll over the gear of thedrum and the'gear of the sleeve 20 that will have to move because of thedifference in diameter of the planet Wheels 23 and 22. The press willtherefore work, but at a relatively reduced speed, although the flywheel l9 maintains its speed, which is given it by the motor,approximately constant.

If, finally, instead of acting on the cheeks 25 and instead of brakingthe drum, the cone 28 is driven in the latter, so as to connect the drumand fly wheel with each other by reason of the clutching effect thusproduced, it will be seen that the shaft 1 will have to rotate at thespeed of the fly wheel, since it will no longer be possible for theplanet wheels 23 to roll over the gear of the drum and consequently tohave an absolute rigidity in the system of transmission just described.This operation corresponds to the rapid working of the press, since thefly wheel maintains substantially the speed given it by the motor,

It is clear that the arrangement described is complete, only when alocking has been provided between the brake of the drum and the cone ofthe clutch to prevent the machine from being jammed or a piece frombeing broken by the simultaneous operation of these two members, whichhave the effect of causing simultaneously the slow and rapid rates ofworking.

In the press shown, another improvement is provided, which comprises atthe same time the above locking.

The slow rate of working of the press is in deed particularly useful forefiecting regulating operations, that is to say, for causing the membersof the latter to advance but a short distance at the time. This, forinstance, is necessary when the press is worked with a printing groupthat must be subjected to minute regulation. There is, however, adrawback which must at all events be avoided when regulating, and thatis the jam- 'ming of the press in the neighbourhood of its dead centre,where it furnishes its productive effort for, when jammed in such aposition, it is extremely difficult to set it going again and in anycase impossible to do so with the sole force furnished by the motor.

In order to prevent this accident, electro-mechanical means are providedwhich oppose any stopping of the press, that is to say any unclutchingof the latter, when its head 2 is in the neighbourhood of its punchingposition, but these electro-mechanical means remain inactive, when thelever I3 is brought into its position 13', and the press is not working.

The means in question are constituted as follows:

To actuate the brake of the drum 24 by means of the lever 30, use ismade of an electro-magnet 3|. To cause the clutching of the drum 24 bymeans of the cone 28 and of the fork 29, use is made of a lever 32 whichacts on a bar 33 and. by means of the lever 34 on the rod 35, the bar 33carrying a contact 36 which closes an electric circuit in the positionshown of these members. Finally, a contact 3'! is provided which israised and lowered at the same time as the head 2 and which can likewiseclose a circuit at its lower dead centre, when the press is working,that is to say when the lever l3 occupies the position shown infull-line. In the other position, the contact 3'! is raised with theconnecting rod [5 and can no longer meet the contacts 38 by means ofwhich it closes the circuit.

If the diagram of Fig. 3 is now consulted, in which are found again partof the elements just described, it will be seen that from a source ofenergy shown by the terminals 39, the electric circuit passes throughthe lead 4!] and the electromagnet 3| to start the slow working, andthen passes through the contact 36 in order to join a lead 41 from whichthe circuit can be closed on the lead 42, either by said contact andcontacts 31, 38, or by one of the switches 43, 44, 45 which are allbranched in parallel,

These switches are nothing else but control buttons which are placed atdifferent points on the press and the object of which is to make itpossible, while regulating and from said points, to start the slow rateof working. In fact, in the position shown of the different parts ofthis diagram, it is only necessary to close one of these switches inorder to energize the electromagnet 3|, to cause the drum 24 to brakeand to obtain the slow rate of working of the press. This is, however,only possible, if the contact 36 closes the circuit, that is to say ifthe lever 32 L occupies the position which is shown in Figs, 1 and 2which corresponds to the removal of the cone 28 and the non-clutching ofthe drum 24 with the fly wheel l9. In the clutching position of thelever 32, the circuit of the electro-magnet can no longer be closed, sothat the accident previously described, resulting from a simultaneousstarting in slow and fast speeds cannot arise.

It is finally to be remarked that the contact 31 and the contact 33 arealso capable of closing the circuit of the electro-magnet and of causingthe slow rate of working. This arises, when the lever I3 is in theworking position of the press and whenever the head of the latter islowered, that is to say working. In fact, whenever the head of the presspasses through its lower dead centre, the contact 31 reaches the contact38 and closes the circuit (as much as the contact 36 is closed), so thateven if at this moment it were necessary to release the switches 43, 44or 45 which are worked for the regulation, the press would continue towork slowly, until it had left this dangerous dead centre. This effectof the contact 3'! does not of course occur in the position l3 of thelever 13. In this position, there is besides no dangerous pressure to beovercome, since the press is working idle.

In short, the operation of the press described is extremely simple, onthe one hand, motor and fly wheel maintain substantially a constantspeed, whatever the operations executed. Then for normal rapid work, thepress is clutched by means of the lever 32, whereas when it is beingregulated, it can be caused to rotate slowly and at a rate just fastenough for the regulating operations, by actuating any of the switcheswhich are placed anywhere on the press, and thus any jamming due tofaulty operation is automatically avoided.

It is clear that the contacts 31, 38 act, even if the fast speed isunclutched by means of the lever 32 at the precise moment, when thepress could be jammed. In this position and at this moment, the press isautomatically put into and said clutch means and connecting the same tovsaid press, mechanical means for clutching the fast speed of the clutchmeans to said shaft means for driving said press and electro-magneticmeans for clutching the slow speed of said clutch means to said shaft,said electro-magnetic means comprising an electrical circuit having atleast one switch placed at any desired point for causing or interruptingat will the slow speed and another switch controlled by movement of themechanical clutch means so that the circuit is open when the fast speedis thrown into clutch and closed when thrown out of clutch. I

2. A press serving especially for the cutting of cardboard worked in a,continuous web, comprising a movable press head cooperating with asupport for cutting said cardboard and having a flywheel, means forrotating said flywheel at a substantially constant speed, a two speedclutch means placed between said flywheel and said press, a shaft foraxially supporting said flywheel and said clutch means and connectingthe same to said press, mechanical means for clutching the fast speed ofthe clutch means to said shaft for driving said press, andelectro-magnetic means for clutching the slow speed of said clutch meansto said shaft, said electro-magnetic means comprising an electricalcircuit having at least one switch placed at any desired point forcausing or interrupting at will the slow speed and another switchcontrolled by movement of the mechanical clutching means so that thecircuit is open when the fast speed is thrown into clutch and closedwhen thrown out of clutch, said electro-magnetic circuit also includingan additional switch mpans connected to said press head for operatingsaid additional switch when said press is in the neighborhood of deadcenter so that the clutch is thrown in slow speed during the time whenthe press is passing dead center.

3. A press serving especially for the cutting of cardboard worked in acontinuous web comprising a movable press head cooperating with asupport for cutting said cardboard and having a flywheel, means forrotating said flywheel at a substantially constant speed, a two speedclutch means placed between said flywheel and said press, a shaft foraxially supporting said flywheel and said clutch means and connectingthe same to said press, and means for preventing the press from stoppingin the neighborhood of dead center, said flywheel carrying two groups ofplanet wheels with pinions of one of said groups rolling on a gear whichis integral with the drum of a brake, means for mechanically connectingsaid brake to said flywheel and electrical means for applying saidbrake.

4. A press, serving especially for the cuttin of cardboard worked in acontinuous web, com- HENRI BOBST.

